By -
Date 09-20-2005 13:38
Hydrogen is not recommended for welding the ferritic and martensitic stainless steels due to the disolved hydrogen and high ferrites can cause hydrogen cracking. Additions of more than 5% hydrogen can cause porosity in the weld pool.
Shielding gases for TIG welding:
Ferritic and martensitic--1st choice: argon, 2nd choice:argon + 30% helium
standard austenitics (304, 316, etc)--1st choice:argon, 2nd choice:argon + 30% helium, 3rd choice:argon + 2% hydrogen
Fully austenitics (254 SMO, etc)--1st choice:Argon, 2nd choice:Argon+ 2%N2, 3rd choice:Ar +30% He+2% N2
Duplex (2205, 2507)--1st choice:Ar, 2nd choice:Ar +2% N2, 3rd choice: Ar+30%He+2%N2
Nickel based alloys (625, 800)--1st choice:Ar, 2nd choice:Ar+30%He
Chuck